Apparatus and method for reporting system frame number (SFN) and subframe offset in dual connectivity (DC) enhancement

ABSTRACT

Embodiments of a user equipment (UE) for reporting of timing offset for dual connectivity enhancement are disclosed herein. The UE can include transceiver circuitry to connect to a master cell group via a master evolved node B (eNB) and a secondary cell group via a secondary eNB. Additionally, the UE can receive a first reference signal from the master eNB and a second reference signal from a secondary eNB. Moreover, the UE can include processing circuitry to calculate a system frame number (SFN) and subframe timing difference (SSTD) based on the first reference signal and the second reference signal. Moreover, the UE can generate a measurement report having a synchronization indicator for dual connectivity based on the calculated SSTD. Subsequently, the UE can send the generated measurement report to the master eNB.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.15/755,529, filed Feb. 26, 2018, which is a U.S. National StageApplication under U.S.C. 371 from International Application No.PCT/US2015/066631, filed Dec. 18, 2015, which claims priority to U.S.Provisional Patent Application Ser. No. 62/210,717, filed Aug. 27, 2015,each of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

Embodiments pertain to wireless communications. Some embodiments relateto cellular communication networks, including networks configured tooperate in accordance with the third-generation partnership project(3GPP) long term evolution (LTE) and LTE-advanced (LTE-A) standards.

BACKGROUND

Current issues with communicating data over a wireless network caninclude low throughput, frequent handovers, handover failures,inefficient offloads, and service interruptions.

Dual connectivity (DC) in an LTE network can significantly improveper-user throughput, reduce handovers, and reduce handover failures byallowing a user to be connected simultaneously to a master cell groupand a secondary cell group via a macro evolved Node B (eNB) and a smallcell eNB.

With regards to low throughput, dual connectivity can increase per-userthroughput by aggregating radio resources from at least two eNBs.Additionally, throughput can be increased by transmitting or receivingmultiple streams and dynamically adapting to the best radio conditionsof multiple cells. Also, small cell eNBs can provide additional capacityfor UEs having multiple radio connections.

Moreover, moving UEs suffer frequent handover failure, inefficientoffload, and service interruption. The consequences are more severe ifthe UE's velocity is higher and cell coverage is smaller. Dualconnectivity can reduce the handover failure rate by maintaining themacro eNB (e.g., primary cell) connection as the coverage layer. Dualconnectivity also helps in load balancing between the macro eNB and thesmall cell eNB secondary cell).

Furthermore, dual connectivity can reduce signaling overhead towards thecore network due to frequent handover. For example, signaling overheadcan be reduced by not issuing handover operations as long as the UE iswithin macro coverage.

However, dual connectivity can impose several technical challenges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional diagram of a 3GPP network, in accordance withsome embodiments;

FIG. 2 is a functional diagram of a UE, in accordance with someembodiments;

FIG. 3 is a functional diagram of an eNB, in accordance with someembodiments;

FIG. 4 illustrates an example of an offset measurement report generatedby a UE, in accordance with some embodiments;

FIG. 5 illustrates an example of a communication 500 of a UE, MeNB, anda SeNB in DC enhancement, in accordance with some embodiments;

FIG. 6 illustrates an example flowchart for calculating the subframeboundary offset (SBO), in accordance with some embodiments;

FIG. 7 illustrates the operation of a method performed by a UE togenerate a measurement report, and send the measurement report to aneNB, in accordance with some embodiments;

FIG. 8 illustrates the operation of a method performed by an eNB todetermine a subframe boundary alignment based on a received measurementreport, in accordance with some embodiments;

FIG. 9 illustrates an example of a MeasResults information element sentby a UE, in accordance with some embodiments;

FIG. 10 is an example of a RRCConnectionReconfiguration message sent bya eNB, in accordance with some embodiments;

FIGS. 11 and 12 illustrate examples for SCG measurement gapconfiguration, in accordance with some embodiments;

FIG. 13 is a block diagram illustrating components of a machine,according to some example embodiments, able to read instructions from amachine-readable medium and perform any one or more of the methodologiesdiscussed herein; and

FIG. 14 illustrates example components of a UE, in accordance to someexample embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

In this disclosure, embodiments are often discussed with reference to amaster eNB and a secondary eNB. Additionally, various embodimentsdisclosed herein are applicable in other settings with otherterminology. For example, a master eNB can be denoted as an “anchoreNB,” “primary eNB,” or “macro eNB,” while a secondary eNB can bedenoted as an “assisting eNB,” “macro eNB,” or “slave eNB.”

In current implementations, the UE can measure an SFN and sub framedifference between the master eNB (MeNB) and the secondary eNB (SeNB)for dual connectivity. For example, the SFN and subframe timing offsetcan be determined and reported by the network.

However, in a multi-vendor deployment, a drawback can include the UE notobtaining the SFN and subframe timing offset information from thenetwork. In the multi-vendor deployment example, the different vendorsmay not have network coordination via different operations andmanagement (OAM) for DC. Therefore, the network may not be able toobtain the SFN and subframe timing offset information.

According to some embodiments, techniques for UE based reporting on SFNand subframe offset between MeNB and SeNB are described herein.

As an overview, FIGS. 1-3 illustrate functional diagrams of an exemplary3GPP network, a UE, and an eNB, respectively.

FIG. 1 is a functional diagram of a 3GPP network, in accordance withsome embodiments. The network comprises a radio access network (RAN)(e.g., as depicted, the E-UTRAN or evolved universal terrestrial radioaccess network) 100 and a core network 120 (e.g., shown as an EPC)coupled together through an S1 interface 115. For the sake ofconvenience and brevity, only a portion of the core network 120, as wellas the RAN 100, is shown.

The core network 120 includes a mobility management entity (MME) 122,serving gateway (serving GW) 124, and a packet data network gateway (PDNGW) 126. The RAN 100 includes eNBs 104 (which may operate as basestations) for communicating with UEs 102. The eNBs 104 may include macroeNBs and low power (LP) eNBs, such as micro eNBs.

The MME 122 is similar in function to the control plane of legacyServing GPRS Support Nodes (SGSN). The MME 122 manages mobility aspectsin access such as GW selection and tracking area list management. Theserving GW 124 terminates the interface toward the RAN 100, and routesdata packets between the RAN 100 and the core network 120. In addition,it may be a local mobility anchor point for inter-eNB handovers and alsomay provide an anchor for inter-3GPP mobility. Other responsibilitiesmay include lawful intercept, charging, and some policy enforcement. Theserving GW 124 and the MME 122 may be implemented in one physical nodeor separate physical nodes. The PDN GW 126 terminates a SGi interfacetoward the PDN. The PDN GW 126 routes data packets between the corenetwork 120 and the external PDN, and may be a key node for policyenforcement and charging data collection. It may also provide an anchorpoint for mobility with non-LTE accesses. Time external PDN can be anykind of IP network, as well as an IMS domain. The PDN GW 126 and theserving GW 124 may be implemented in one physical node or separatephysical nodes.

The eNBs 104 terminate the air interface protocol and may be the firstpoint of contact for a UE 102. In some embodiments, an eNB 104 mayfulfill various logical functions for the RAN 100 including but notlimited to RNC (radio network controller functions) such as radio bearermanagement uplink and downlink dynamic radio resource management anddata packet scheduling, and mobility management. In accordance withembodiments, UEs 102 may be configured to communicate orthogonalfrequency-division multiplexing (OFDM) communication signals with an eNB104 over a multicarrier communication channel in accordance with anorthogonal frequency-division multiple access (OFDMA) communicationtechnique. The OFDM signals may comprise a plurality of orthogonalsubcarriers.

The S1 interface 115 is the interface that separates the RAN 100 and thecore network 120. It is split into two parts: the S1-U, which carriesdata traffic between the eNBs 104 and the serving GW 124, and theS1-MME, which is a signaling interface between the eNBs 104 and the MME122. The X2 interface is the interface between eNBs 104. The X2interface comprises two parts, the X2-C and X2-U. The X2-C is thecontrol plane interface between the eNBs 104, while the X2-U is the userplane interface between the eNBs 104.

In cellular networks, low power (LP) cells are typically used to extendcoverage to indoor areas where outdoor signals do not reach well, or toadd network capacity in areas with dense phone usage, such as trainstations. As used herein, the term “LP eNB” refers to any suitablerelatively low power eNB for implementing a narrower cell (narrower thana macro cell) such as a femtocell, a picocell, or a micro cell.Femtocell eNBs 104 are typically provided by a mobile network operatorto its residential or enterprise customers. A femtocell is typically thesize of a residential gateway or smaller and generally connects to theuser's broadband line. In some instances, a home eNB gateway may beinserted between a home eNB 104 (e.g., femtocell eNB) and the MME 122and serving gateway 124. The home eNB gateway can control several homeeNBs 104 and concentrates the user data and signaling traffic from thehome eNBs 104 towards the MME 122 and serving gateway 124. Similarly, apicocell is a wireless communication system typically covering a smallarea, such as in-building (offices, shopping malls, train stations,etc.), or, more recently, in-aircraft. A picocell eNB 104 can generallyconnect through the X2 link to another eNB 104, such as a macro eNB 104,through its base station controller (BSC) functionality. Additionally,the picocell eNB 104 is connected via an S1 interface to an MME 122 orservice gateway 124. Thus, an LP eNB 104 may be implemented with apicocell eNB 104 since it is coupled to a macro eNB 104 via an X2interface. Picocell eNBs 104 or other LP eNBs 104 may incorporate someor all functionality of a macro eNB 104. In some cases, this may bereferred to as an access point base station or enterprise femtocell.

In some embodiments, a downlink resource grid may be used for downlinktransmissions from an eNB 104 to a UE 102, while uplink transmissionsfrom the UE 102 to the eNB 104 may utilize similar techniques. The gridmay be a time-frequency grid, called a resource grid or time-frequencyresource grid, which is the physical resource in the downlink in eachslot. Such a time-frequency plane representation is common for OFDMsystems, which makes it intuitive for radio resource allocation. Eachcolumn and each row of the resource grid correspond to one OFDM symboland one OFDM subcarrier, respectively. The duration of the resource gridin the time domain corresponds to one slot in a radio frame. Thesmallest time-frequency unit in a resource grid is denoted as a resourceelement. Each resource grid comprises a number of resource blocks, whichdescribe the mapping of certain physical channels to resource elements.There are several different physical downlink channels that are conveyedusing such resource blocks. With particular relevance to thisdisclosure, two of these physical downlink channels are the physicaldownlink shared channel (PDSCH) and the physical downlink controlchannel (PDCCH).

The PDSCH carries user data and higher-layer signaling to a LIE 102. ThePDCCH carries information about the transport format and resourceallocations related to the PDSCH channel, among other things. It alsoinforms the UE 102 about the transport format, resource allocation, andhybrid automatic repeat request (HARQ) information related to the uplinkshared channel. Typically, downlink scheduling (assigning control andshared channel resource blocks to UEs 102 within a cell) is performed atthe eNB 104 based on channel quality information fed back from the UEs102 to the eNB 104, and then the downlink resource assignmentinformation is sent to a LIE 102 on the PDCCH used for (assigned to) theUE 102.

The PDCCH uses control channel elements (CCEs) to convey the controlinformation. Before being mapped to resource elements, the PDCCHcomplex-valued symbols are first organized into quadruplets, which arethen permuted using a sub-block inter-leaver for rate matching. EachPDCCH is transmitted using one or more of these CCEs, where each CCEcorresponds to nine sets of four physical resource elements known asresource element groups (REGs). Four quadrature phase-shift keying(QPSK) symbols are mapped to each REG. The PDCCH can be transmittedusing one or more CCEs, depending on the size of DCI and the channelcondition. There may be four or more different PDCCH formats defined inLTE with different numbers of CCEs (e.g., aggregation level L=1, 2, 4,or 8).

FIG. 2 is a functional diagram of a UE 200, in accordance with someembodiments. FIG. 3 is a functional diagram of an evolved node-B (eNB)300, in accordance with some embodiments. The UE 200 can be a UE 102 asdepicted in FIG. 1, while the eNB 300 can be an eNB 104 as depicted inFIG. 1.

The LIE 200 can include physical layer circuitry 202 for transmittingand receiving signals to and from the eNB 300, other eNBs, other UEs, orother devices using one or more antennas 201, while the eNB 300 caninclude physical layer circuitry 302 for transmitting and receivingsignals to and from the UE 200, other eNBs, other UEs, or other devicesusing one or more antennas 301.

The UE 200 can also include medium access control layer (MAC) circuitry204 for controlling access to the wireless medium, while the eNB 300 canalso include MAC circuitry 304 for controlling access to the wirelessmedium.

The UE 200 can also include processing circuitry 206 and memory 208arranged to perform the operations described herein, and the eNB 300 canalso include processing circuitry 306 and memory 308 arranged to performthe operations described herein.

The UE 200 can include an offset calculator 210 which interfaces withother components of the UE 200 (e.g., antenna 201, PHY 202, and MAC 204,processing circuitry 206, memory 208) to communicate with the eNB 300via a radio interface. Additionally, the offset calculator 210 can haveprocessing circuitry and memory and interfaces to communicate with theother components of the UE 200 via one or more internal interfaces.

The eNB 300 can also include one or more interfaces 310, which canenable communication with other components, including other eNBs 104(FIG. 1), components in the core network 120 (FIG. 1), or other networkcomponents. In addition, the interfaces 310 can enable communicationwith other components that may not be shown in FIG. 1, includingcomponents external to the network. The interfaces 310 may be wired,wireless, or a combination thereof.

The antennas 201, 301 may comprise one or more directional oromnidirectional antennas, including, for example, dipole antennas,monopole antennas, patch antennas, loop antennas, microstrip antennas,or other types of antennas suitable for transmission of radio frequency(RF) signals. In some multiple-input multiple-output (MIMO) embodiments,the antennas 201, 301 may be effectively separated to take advantage ofspatial diversity and the different channel characteristics that mayresult.

In some embodiments, mobile devices or other devices described hereinmay be part of a portable wireless communication device, such as apersonal digital assistant (PDA), a laptop or portable computer withwireless communication capability, a web tablet, a wireless telephone, asmartphone, a wireless headset, a pager, an instant messaging device, adigital camera, an access point, a television, a medical device (e.g., aheart rate monitor, a blood pressure monitor, etc.), or another deviceincluding wearable devices that may receive and/or transmit informationwirelessly. In some embodiments, the mobile device or other device canbe a UE 200 or an eNB 300 configured to operate in accordance with 3GPPstandards. In some embodiments, the mobile device or other device may beconfigured to operate according to other protocols or standards,including IEEE 802.11 or other IEEE standards. In some embodiments, themobile device or other device may include one or more of a keyboard, adisplay, a non-volatile memory port, multiple antennas 201, 301, agraphics processor, an application processor, speakers, and other mobiledevice elements. The display may be a liquid crystal display (LCD)screen including a touch screen.

Although the LIE 200 and the eNB 300 are each illustrated as havingseveral separate functional elements, one or more of the functionalelements may be combined and may be implemented by combinations ofsoftware-configured elements, such as processing elements includingdigital signal processors (DSPs), and/or other hardware elements. Forexample, some elements may comprise one or more microprocessors, DSPs,field-programmable gate arrays (FPGAs), application specific integratedcircuits (ASICs), radio-frequency integrated circuits (RFICs), andcombinations of various hardware and logic circuitry for performing atleast the functions described herein. In some embodiments, thefunctional elements may refer to one or more processes operating on oneor more processing elements.

Embodiments may be implemented in one or a combination of hardware,firmware, and software. Embodiments may also be implemented asinstructions stored on a computer-readable storage device, which may beread and executed by at least one processor to perform the operationsdescribed herein. A computer-readable storage device may include anynon-transitory mechanism for storing information in a form readable by amachine (e.g., a computer). For example, a computer-readable storagedevice may include read-only memory (ROM), random-access memory (RAM),magnetic disk storage media, optical storage media, flash-memorydevices, and other storage devices and media. Some embodiments mayinclude one or more processors that may be configured with instructionsstored on a computer-readable storage device.

In some embodiments, the UE 200 may be configured to receive OFDMcommunication signals over a multicarrier communication channel inaccordance with an OFDMA communication technique. The OFDM signals maycomprise a plurality of orthogonal subcarriers. In some broadbandmulticarrier embodiments, the eNB 300 may be part of a broadbandwireless access (BWA) communication network, such as a WorldwideInteroperability for Microwave Access (WiMAX) communication network, a3GPP Universal Terrestrial Radio Access Network (UTRAN) LTE network, ora LTE communication network, although the scope of this disclosure isnot limited in this respect. In these broadband multicarrierembodiments, the LIE 200 and the eNB 300 may be configured tocommunicate in accordance with an OFDMA technique.

SFN and Subframe Timing Difference (SSTD) in DC Enhancement

FIG. 4 illustrates an example of an offset measurement report 400, inaccordance with some embodiments. The offset measurement report 400 canalso be simply referred as the measurement report. As will beillustrated in FIG. 5, the UE 102 can receive reference signals from amaster eNB 104 (MeNB) and a secondary eNB 104 (SeNB). Subsequently, theUE 102 can calculate the measurement report 400 based on the receivedreference signals, and sent the measurement report 400 to the MeNB.

According to some embodiments, the measurement report 400 can include aSFN and subframe timing difference (SSTD) 410 in DC enhancement. TheSSTD 410 can include: a SFN offset between MeNB and SeNB (SFNO) 420; (2)a frame boundary offset between MeNB and SeNB (FBO) 430; or a subframeboundary offset (SBO) 440. In some instances, the SSTD 410 can includethe SFNO 420, the FBO 430, and the SBO 440. In some instances, thereporting range for the SFNO can be [−512, 511) in frame In someinstances, the reporting range for FBO 430 can be [−5, 5) in subframe.

According to some embodiments, the measurement report 400 can include asynchronization indicator 450. The synchronization indicator 450 canindicate whether that the MeNB and the SeNB are synchronous to eachother. In some instances, when the UE 102 cannot determine whether theMeNB and the SeNB are synchronous or asynchronous, then thesynchronization indicator 450 can be quantized as later described inTable 1.

For example, the subframe timing difference between the MeNB and theSeNB can measured by UE 102, and denoted by T_subframeoffset. When theT_subframeoffset is less than 33 μs minus a margin value, the UE 102 canreport a ‘sync’ notification to the network. Additionally, when theT_subframeoffset is greater than 33 μs plus a margin value, the UE 102can report an ‘async’ notification to the network Otherwise, theT_subframeoffset can be quantized and reported to the network. In someinstances, the margin value is received by a network entity. Forexample, the margin value can be predetermined by the network operator,and sent to the UE 102 by a network entity.

In some instances, the UE 200, using the timing offset apparatus, candetermine the SSTD 410, the SFNO 420, the FBO 430, the SBO 440, and thesynchronization indicator 450. The timing offset apparatus can calculatethe offset information for the measurement report 400 based on theinformation from the reference signals received from the MeNB and theSeNB. The reference signals can be received by the UE 102's transceiveror physical layer circuitry 202.

Example UE Reporting on SFN and Subframe Offset in DC in LTE

FIG. 5 illustrates an example of a communication 500 of a UE 501, a MeNB502, and a SeNB 503 in DC enhancement, in accordance with someembodiments. The communication 500 can be reporting procedures for SFNand subframe offset in DC enhancement, in accordance with someembodiments. For example, UE 501 can generate a measurement report(e.g., measurement report 400 in FIG. 4) and send the measurement reportto the MeNB 502. The communication 500 can be between a UE 501 (e.g., UE102), a MeNB 502 (e.g., eNB 104), and SeNB 503 (e.g., eNB 104). In theDC enhancement, the UE 501 can connect to a master cell group (MCG) viathe MeNB 502, and the UE 501 can connect to a secondary cell group (SCG)via the SeNB 503.

At operation 510, the UE 501 can receive a first reference signal fromthe MeNB 502. The first reference signal can include a primarysynchronization signal (PSS), a secondary synchronization signal (SSS),a cell-specific Reference signal (CRS), a positioning reference signal(PRS), or a master information block (MIB).

At operation 520, the UE 501 a second reference signal from the SeNB503. Similar to the first reference signal, the second reference signalcan include a PSS, a CRS, a PRS, a SSS, or a MIB.

At operation 530, the UE 501 can calculate the SFN and subframe timingdifference 410 (SSTD) based on the first reference signal and the secondreference signal. Additionally, the UE 501 can generate a measurementreport (e.g., measurement report 400 in FIG. 4) that includes thecalculated SSTD 410 and a synchronization indicator (e.g.,synchronization indicator 450 in FIG. 4). In some instances, themeasurement report 400 may only include the SSTD 410.

As previously mentioned in FIG. 4, the SSTD 410 can include: (1) a SFNoffset between MeNB 502 and SeNB 503 (SFNO 420); (2) a frame boundaryoffset between MeNB 502 and SeNB 503 (FBO 430); or a subframe boundaryoffset 440 (SBO). The SFNO 420, FBO 430, and SBO 440 can be calculatedusing the timing information (e.g., PSS, SSS, CRS, PRS, or MIB) receivedfrom the MeNB 502 and the SeNB 503 via the first and second referencesignals at operations 510 and 520.

In some instances. After the UE 501 synchronized with MeNB 502 and SeNB503 separately, the SFN timing difference between MCG and SCG can becalculated from the received MIBs of MeNB 502 and SeNB 503. The SFNO(e.g., SFNO 420 in FIG. 4) can be determined based on the calculated SFNtiming difference. In some instances, the SFNO (e.g., SFNO 420 in FIG.4) is equal to the SFN timing difference. Equation 1 is an example ofcalculating the SFN timing difference.SFN_offset=SFN_MCG−SFN_SCG [Frame level]  (Eq. 1)

Additionally, the FBO (e.g., FBO 430 in FIG. 4) can be determined basedon the frame boundary timing of MCG and SCG (denoted as “T_mcg” and“T_scg”). The frame boundary timing of MCG and SCG can be measured in Tsunit. For example, Ts, which is a basic time unit defined by 3GPP, isequal to 1/(15000×2048) seconds. Equation 2 is an example of calculatingthe frame boundary timing offset between MCG and SCG, according to someembodiments,T_offset_Frame−T_mcg−T_scg in Ts  (Eq. 2)

Once the FBO (e.g., FBO 430 in FIG. 4) has been calculated, the FBO 430can be reported to the network (e.g., MeNB 502) by the UE 501 insubframe granularity, as later described in Table 1. Equation 3 is anexample of reporting the FBO 430 in subframe granularity, according tosome embodiments.FrameTiming_offset=floor(T_offset_Frame/30720) in milli-seconds(ins)  (Eq. 3)

Moreover, Equation 4 is an example of calculating the subframe boundaryoffset by UE 501, according to some embodiments.Subframe_offset_meas=mod(abs(T_offset_Frame), 30720/2)*1000 (in Ts) orby other UE measurement (e.g. reference signal time difference (RSTD),PRS RSTD, CRS Rx-Tx timing difference)  (Eq. 4)

Subsequently, the SBO (e.g., SBO 440 in FIG. 4) repotting to the MeNB502 can be determined using flowchart 600 in FIG. 6. In some instances,the determinations and calculations in FIG. 6 can be performed using theoffset calculator 210 from FIG. 2.

As illustrated in FIG. 6, at operation 610, the offset calculator 210determines if the Subframe_offset_meas calculated in Equation 4 is lessthan 33 minus the first margin value. As previously mentioned, theSubframe_offset_meas is measured in Ts. The first margin value can besignaling from the network. For example, the first margin value can bepredetermined by the network operator and sent to the UE 501 by the MeNB502 or SeNB 503.

At operation 620, when the Subframe_offset_meas is less than 33 minusthe first margin value, then the SBO 440 can be determined to besynchronous (e.g., SBO=‘SyncDC’).

Alternatively, when the Subframe_offset_meas is not less than 33 minusthe first margin value, then the flowchart 600 continues to operation630.

At operation 630, the offset calculator 210 determines if theSubframe_offset_meas is greater than 33 plus a second margin value. Thesecond margin value can be signaling from the network. For example, thesecond margin value can be predetermined by the network operator andsent to the UE 501 by the MeNB 502 or SeNB 503. In some instances, thefirst margin value can equal to the second margin value. Alternatively,the first margin value can be greater or less than the second marginvalue.

At operation 640, when the Subrame_offset meas is more than 33 plus thesecond margin value, then the SBO 440 can be determined to beasynchronous (e.g., SBO=‘AsyncDC’). In some instances, the reporting ofSBO can be multiple values when “asyncDC”. For example, SBO_1, SBO_2from Table 1 are example reporting values when SBO 440 is determined tobe asynchronous.

Alternatively, when the Subframe_offset_meas is not more than 33 plusthe second margin value, then the flowchart 600 continues to operation650.

At operation 650, the offset calculator 210 can granulize the SBO 440based on Q_step. Similar to the margin values, Q_step can be signaledfrom the network. For example, the Q_step can be predetermined by thenetwork operator and sent to the UE 501 by the MeNB 502 or SeNB 503.Continuing with operation 650, when the offset calculator 210 candetermines the SBO 440 using Equation 5.SBO=floor(Subframe_offset_meas/Q_step)  (Eq. 5)Techniques in Asynchronous in Dual Connectivity Enhancement

FIG. 7 illustrates the operation of a method 700 for synchronizing in DCenhancement mode using a UE-generated measurement report 400, inaccordance with some embodiments. Method 700 can be performed by a UE(e.g., UE 102. UE 200). Embodiments are not limited to theseconfigurations, however, and some or all of the techniques andoperations described herein may be applied to any systems or networks.

It is important to note that embodiments of the method 700 may includeadditional or even fewer operations or processes in comparison to whatis illustrated in FIG. 7. In addition, embodiments of the method 700 arenot necessarily limited to the chronological order that is shown in FIG.7. In describing the method 700, reference may be made to FIGS. 1-6,although it is understood that die method 700 may be practiced with anyother suitable systems, interfaces 310, and components.

In addition, while the method 700 and other methods described herein mayrefer to eNBs 104 or UEs 102 operating in accordance with 3GPP or otherstandards, embodiments of those methods are not limited to just thoseeNBs 104 or UEs 102 and may also be practiced by other mobile devices,such as a Wi-Fi access point (AP) or user station (STA) Moreover, themethod 700 and other methods described herein may be practiced bywireless devices configured to operate in other suitable types ofwireless communication systems, including systems configured to operateaccording to various IEEE standards such as IEEE 802.11.

At operation 710 of the method 700, an apparatus of the UE 102, usingtransceiver circuitry, can connect to a master cell group (MCG) via amaster evolved node B 502 (eNB) and a secondary cell group (SCO) via asecondary eNB 503. As illustrated in FIG. 5, in dual connectivity (DC)enhancement, the UE 501 can be connected to the MCG via the MeNB 502 andthe SCG via the SeNB 503. In some instances, the transceiver circuitrycan be the physical layer circuitry 202 of UE 200 in FIG. 2.

At operation 720, the UE 102, using the transceiver circuitry, canreceive a first reference signal from the master eNB (e.g., MeNB 502 inFIG. 5). Operation 510 in FIG. 5 can be an example of operation 720. Aspreviously mentioned, the transceiver circuitry can be the physicallayer circuitry 202 of UE 200 in FIG. 2.

At operation 730, the LIE 102, using the transceiver circuitry, canreceive a second reference signal from the secondary eNB (e.g., SeNB 503in FIG. 5). Operation 520 in FIG. 5 can be an example of operation 730.As previously mentioned, the transceiver circuitry can be the physicallayer circuitry 202 of UE 200 in FIG. 2.

At operation 740, the LIE 102, using processing circuitry 206 cancalculate a system frame number (SFN) and subframe timing difference 410(SSTD) based on the first reference signal and the second referencesignal. Operation 530 in FIG. 5 can be an example of operation 740. TheSSTD 410 in FIG. 4 is an example of the SSTD 410 calculated at operation740. In some instances, the processing circuitry can be the processingcircuitry 206 of LIE 200 in FIG. 2. In some other instances, the offsetcalculator 210 can perform operation 740.

In some instances, the first reference signal can include a masterinformation block (MIB) having SFN information for the MCG (e.g.,SFN_MCG). Additionally, the second reference signal can include a MIBhaving SFN information for the SCG (e.g., SFN_SCG). Furthermore, theSSTD 410 includes a SFN timing difference between the MCG and the SCGthat is calculated based on the SFN information for the MCG and the SFNinformation for the SCG. For example, the SFN timing difference can bethe SFNO 420, which can be calculated by subtracting the SFN_SCG fromthe SFN_MCG.

At operation 750, the UE 102, using processing circuitry 206, cangenerate a measurement report 400 having a synchronization indicator 450based on the calculated SSTD 410. The measurement report 400 in FIG. 4is an example of the measurement report generated at operation 750. Thesynchronization indicator 450 in FIG. 4 is an example of thesynchronization indicator 450 generated at operation 750. In someinstances, the processing circuitry can be the processing circuitry 206of UE 200 in FIG. 2. In some other instances, the offset calculator 210can perform operation 750.

At operation 760, the UE 102, using the transceiver circuitry, can sendthe generated measurement report 400 to the master eNB. (e.g., MeNB 502in FIG. 5). Operation 550 in FIG. 5 can be an example of operation 760.As previously mentioned, the transceiver circuitry can be the physicallayer circuitry 202 of UE 200 in FIG. 2.

In some instances, the first reference signal includes a frame boundarytiming of the MCG and the second reference signal includes a frameboundary timing of the SCG. Additionally, the SSTD 410 includes a frameboundary offset (e.g., FBO 430) between the MCG and the SCG that can becalculated based on the frame boundary timing of the MCG and the frameboundary timing of the SCG. For example, the frame boundary offsetbetween the MCG and the SCG is calculated by subtracting the frameboundary timing of the SCG from the frame boundary timing of the MCG.Furthermore, the method 700 can further include the transceivercircuitry being further configured to receive, from the MeNB 502, amargin value, where the synchronization indicator 450 is further basedon the received margin value. The margin value can be predetermined by anetwork operator associated with the MeNB 502.

In some instances, the SSTD 410 can include a subframe boundary offsetmeasurement, the subframe boundary offset measurement being calculatedfrom the frame boundary timing between the MCG and the SCG. For example,the SBO 440 is an example of the subframe boundary offset measurement.

In some instances, the synchronization indicator 450 can indicate thatthe MCG and the SCG are synchronous when the subframe boundary offsetmeasurement, in addition to the received margin value, is less than 33microseconds.

In some instances, the synchronization indicator 450 can indicate thatthe MCG and the SCG are asynchronous when the subframe boundary offsetmeasurement minus the received margin value is more than 33micro-seconds.

FIG. 8 illustrates the operation of a method 800 for enabling a MeNB 502to synchronize during DC enhancement using a UE-generated measurementreport 400, in accordance with some embodiments. Method 800 can beperformed by an eNB (e.g., eNB 104). In some instances, method 800 canbe performed by a MME (e.g., MME 122). It is important to note thatembodiments of the method 800 may include additional or even feweroperations or processes in comparison to what is illustrated in FIG. 8.In addition, embodiments of the method 800 are not necessarily limitedto the chronological order that is shown in FIG. 8. In describing themethod 800, reference may be made to FIGS. 1-7, although it isunderstood that the method 800 may be practiced with any other suitablesystems, interfaces 310, and components.

In addition, while the method 800 and other methods described herein mayrefer to the eNB 104 operating in accordance with 3GPP or otherstandards, embodiments of those methods are not limited to just thosethe eNB 104 and may also be practiced by a. MME 122, or other mobiledevices, such as a Wi-Fi AP or STA. Moreover, the method 800, and othermethods described herein, may be practiced by wireless devicesconfigured to operate in other suitable types of wireless communicationsystems, including systems configured to operate according to variousIEEE standards such as IEEE 802.11.

The method 800 can be performed by an apparatus of a eNB 104 configuredto operate as a master eNB 502 in a dual connectivity (DC) mode.

At operation 810, the apparatus of the eNB 104, using transceivercircuitry, can receive, from a user equipment 102 (UE), a measurementreport 400. The measurement report 400 can have a system frame number(SFN) and subframe timing difference (SSTD), such as SSTD 410. Method700 of FIG. 7 illustrates the example of the UE 102 sending measurementreport 400 having the SSTD 410. The transceiver circuitry of eNB 104 forperforming operation 810 can be similar to the physical layer circuitry302 in FIG. 3.

At operation 820, the apparatus of the eNB 104, using processingcircuitry 206, can determine a subframe boundary alignment of the mastereNB 502 and a secondary eNB 503 based on the received measurement report400. The processing circuitry of eNB 104 for performing operation 820can be similar to the physical layer circuitry 302 in FIG. 3.

At operation 830, the apparatus of the eNB 104, using the transceivercircuitry, can send the determined subframe boundary alignment. Thetransceiver circuitry of eNB 104 for performing operation 810 can besimilar to the physical layer circuitry 302 in FIG. 3.

In some instances, the determined subframe boundary alignment can besent using radio resource control (RRC) signaling.

Additionally, method 800 can include an operation where the processingcircuitry 306 is further configured to determine a quantized step basedon the determined subframe boundary alignment. Furthermore, thetransceiver circuitry can be further configured to send the determinedquantized step.

Moreover, method 800 can include an operation where the processingcircuitry 306 of the eNB 104 is further configured to determine adiscontinuous reception (DRX) pattern based on the determined subframeboundary alignment, and the transceiver circuitry is further configuredto send the determined DRX pattern.

Signaling Between the UE and the MeNB

According to some embodiments, the UE (e.g., UE 501) can send the offsettiming information (e.g., measurement report 400) to the MeNB MeNB 502)using radio resource control (RRC) signaling. In some instances, theMeasResults information element (in 3GPP specification 36.331) caninclude parameters for the SFNO 420, the FBO 430, the SBO 440, and thesynchronization indicator 450. FIG. 9 illustrates an example of theMeasResults information element 900.

Additionally, the parameters for subframe boundary alignment can beconfigured by die MeNB 502. For example, the MeNB 502 can send theparameters to the UE 501 using the RCC signaling example in FIG. 10. Asillustrated in FIG. 10, the MeNB 502 can send anRRCConnectionReconfiguration message 1000.

Moreover, the reporting map of the SSTD 410 can be specified in 3GPPspecification 36.133. In some instances, the reporting range of SSTD 410may be specified only for the SBO 440. Table 1 is an example of the SBOmeasurement report mapping.

TABLE 1 SBO Measurement Report Mapping REPORTED VALUE MEASURED QUANTITYVALUE SBO_0 SyncDC SBO_1 Floor(Subframe_offset_measIQ_step) SBO_2Floor(Subframe_offset_measIQ_step) . . . SBO_N−1Floor(Subframe_offset_measIQ_step) SBO_N AsyncDC

According to some embodiments, based on the SSTD 410 reporting (e.g.,received measurement report 400), the MeNB 502 can align the measurementgap and DRX pattern for both the MCG and SCG according to the procedurebelow. In addition, techniques performed by the MeNB 502 based on thereceived measurement report 400 are not necessarily limited to theprocedure below. For example, other techniques can be performed by theMeNB 502 to synchronize the MCG and the SCG.

FIGS. 11 and 12 illustrate examples for SCG measurement gapconfiguration. FIG. 11 illustrates a method 1100 for measurement gapalignment, when the SCG is ahead of the MCG. In this example, themeasurement report 400 generated by the 13E 501 can include a sf_offsetthat is equal to “2.” Therefore, during the measurement gap alignmentprocess, the MeNB 502 can re-align the MCG and the SCG based on thereceived the measurement report 400 having information that the SCG isahead of the MCG by 2 subframes. As previously mentioned, the SFNO 420can be obtained by MIBs of MCG and SCG SNF_offsets=SFN in MIB_MCG-SFN inMIB_SCG)

Additionally, FIG. 12 illustrates a method 1200 for measurement gapalignment when the SCG is behind the MCG. In this example, themeasurement report 400 generated by the UE 501 can include a sf_offset1210 that is equal to “−3.” Therefore, during the measurement gapalignment process, the MeNB 502 can re-align the MCG and the SCG basedon the received measurement report 400 having information that the SCGis behind of the MCG by 3 subframes.

Computer Hardware

FIG. 13 illustrates a block diagram of an example machine 1300 uponwhich any one or more of the techniques (e.g., methodologies) discussedherein may perform. In alternative embodiments, the machine 1300 mayoperate as a standalone device or may be connected (e.g., networked) toother machines. In a networked deployment, the machine 1300 may operatein the capacity of a server machine, a client machine, or both inserver-client network environments. In an example, the machine 1300 mayact as a peer machine in peer-to-peer (P2P) (or other distributed)network environment. The machine 1300 may be a UE (e.g., UE 200, UE501), the offset calculator 210, an eNB (e.g., eNB 300, MeNB 502),personal computer (PC), a tablet PC, a set-top box (STB), a personaldigital assistant (PDA), a mobile telephone, a smart phone, a webappliance, a network router, switch or bridge, or any machine capable ofexecuting instructions (sequential or otherwise) that specify actions tobe taken by that machine 1300. Further, while only a single machine 1300is illustrated, the term “machine” shall also be taken to include anycollection of machines 1300 that individually or jointly execute a set(or multiple sets) of instructions to perform any one or more of themethodologies discussed herein, such as cloud computing, software as aservice (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a machine readable medium. In an example, thesoftware, when executed by the underlying hardware of the module, causesthe hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Softwaremay accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Machine (e.g., computer system) 1300 may include a hardware processor1302 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 1304 and a static memory 1306, some or all of which maycommunicate with each other via an interlink (e.g., bus) 1308. Themachine 1300 may further include a video display 1310, an alphanumericinput device 1312 (e.g., a keyboard), and a user interface (UI)navigation device 1314 (e.g., a mouse). In an example, the video display1310, input device 1312 and UI navigation device 1314 may be a touchscreen display. The machine 1300 may additionally include a storagedevice (e.g., drive unit) 1316, a signal generation device 1318 (e.g., aspeaker), a network interface device 1320, and one or more sensors 1321,such as a Global Positioning System (GPS) sensor, compass,accelerometer, or other sensor. The machine 1300 may include an outputcontroller 1328, such as a serial (e.g., universal serial bus (USB),parallel, or other wired or wireless (e.g., infrared (IR), near fieldcommunication (NEC), etc.) connection to communicate or control one ormore peripheral devices (e.g., a printer, card reader, etc.).

The storage device 1316 may include a machine readable medium 1322 onwhich is stored one or more sets of data structures or instructions 1324(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 1324 may alsoreside, completely or at least partially, within the main memory 1304,within static memory 1306, or within the hardware processor 1302 duringexecution thereof by the machine 1300. In an example, one or anycombination of the hardware processor 1302, the main memory 1304, thestatic memory 1306, or the storage device 1316 may constitute machinereadable media 1322.

While the machine readable medium 1322 is illustrated as a singlemedium, the term “machine readable medium” may include a single mediumor multiple media e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 1324.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions 1324 forexecution by the machine 1300 and that cause the machine 1300 to performany one or more of the techniques of the present disclosure, or that iscapable of storing, encoding or carrying data structures used by orassociated with such instructions 1324. Non-limiting machine readablemedium 1322 examples may include solid-state memories, and optical andmagnetic media. Specific examples of machine readable media 1322 mayinclude: non-volatile memory, such as semiconductor memory devices(e.g., electrically programmable read-only memory (EPROM), electricallyerasable programmable read-only memory (EEPROM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; random access memory (RAM); and CD-ROM andDVD-ROM disks. In some examples, machine readable media 1322 may includenon-transitory machine readable media. In some examples, machinereadable media 1322 may include machine readable media 1322 that is nota transitory propagating signal.

The instructions 1324 may further be transmitted or received over acommunications network 1326 using a transmission medium via the networkinterface device 1320 utilizing any one of a number of transferprotocols (e.g., frame relay, interact protocol (IP), transmissioncontrol protocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), plain old telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards, a LongTerm Evolution (LTE) family of standards, a Universal MobileTelecommunications System (UMTS) family of standards, peer-to-peer (P2P)networks, among others. In an example, the network interface device 1320may include one or more physical jacks (e.g., Ethernet, coaxial, orphone jacks) or one or more antennas 201, 301 to connect to thecommunications network 1326. In an example, the network interface device1320 may include a plurality of antennas 201, 301 to wirelesslycommunicate using at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. In some examples, the network interface device 1320may wirelessly communicate using multiple user MIMO techniques. The term“transmission medium” shall be taken to include any intangible mediumthat is capable of storing, encoding or carrying instructions 1324 forexecution by the machine 1300, and includes digital or analogcommunications signals or other intangible medium to facilitatecommunication of such software.

Example UE

As used herein, the term “circuitry” may refer to, be part of, orinclude an Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group), and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablehardware components that provide the described functionality. In someembodiments, the circuitry may be implemented in, or functionsassociated with the circuitry may be implemented by, one or moresoftware or firmware modules. In some embodiments, circuitry may includelogic, at least partially operable in hardware.

Embodiments described herein may be implemented into a system using anysuitably configured hardware and/or software. FIG. 14 illustrates, forone embodiment, example components of a User Equipment (UE) device 1400.In some instances, LIE device 1400 can be the UE 102 or UE 200. In someembodiments, the UE device 1400 may include application circuitry 1402,baseband circuitry 1404, Radio Frequency (RF) circuitry 1406, front-endmodule (FEM) circuitry 1408 and one or more antennas 1410, coupledtogether least as shown.

The application circuitry 1402 may include one or more applicationprocessors. For example, the application circuitry 1402 may includecircuitry such as, but not limited to, one or more single-core ormulti-core processors. The processor(s) may include any combination ofgeneral-purpose processors and dedicated processors (e.g., graphicsprocessors, application processors, etc.). The processors may be coupledwith and/or may include memory/storage and may be configured to executeinstructions stored in the memory/storage to enable various applicationsand/or operating systems to run on the system.

The baseband circuitry 1404 may include circuitry such as, but notlimited to, one or more single-core or multi-core processors. Thebaseband circuitry 1404 may include one or more baseband processorsand/or control logic to process baseband signals received from a receivesignal path of the RF circuitry 1406 and to generate baseband signalsfor a transmit signal path of the RF circuitry 1406. Baseband processingcircuitry 1404 may interface with the application circuitry 1402 forgeneration and processing of the baseband signals and for controllingoperations of the RF circuitry 1406. For example, in some embodiments,the baseband circuitry 1404 may include a second generation (2G)baseband processor 1404 a, third generation (3G) baseband processor 1404b, fourth generation (4G) baseband processor 1404 c, and/or otherbaseband processor(s) 1404 d for other existing generations, generationsin development or to be developed in the future (e.g., fifth generation(5G), 6G, etc.). The baseband circuitry 1404 (e.g., one or more ofbaseband processors 1404 a-d) may handle various radio control functionsthat enable communication with one or more radio networks via the RFcircuitry 1406. The radio control functions may include, but are notlimited to, signal modulation/demodulation, encoding/decoding, radiofrequency shifting, etc. In some embodiments, modulation/demodulationcircuitry of the baseband circuitry 1404 may include Fast-FourierTransform (FFT), precoding, and/or constellation mapping/demappingfunctionality. In some embodiments, encoding/decoding circuitry of thebaseband circuitry 1404 may include convolution, tail-bitingconvolution, turbo, Viterbi, and/or Low Density Parity Check (LDDC)encoder/decoder functionality. Embodiments of modulation/demodulationand encoder/decoder functionality are not limited to these examples andmay include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry 1404 may include elements ofa protocol stack such as, for example, elements of an evolved universalterrestrial radio access network (EUTRAN) protocol including, forexample, physical (PHY), media access control (MAC), radio link control(RLC), packet data convergence protocol (PDCP), and/or radio resourcecontrol (RRC) elements. A central processing unit (CPU) 1404 e of thebaseband circuitry 1404 may be configured to run elements of theprotocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRClayers. In some embodiments, the baseband circuitry may include one ormore audio digital signal processor(s) (DSP) 1404 f. The audio DSP(s)1404 f may be include elements for compression/decompression and echocancellation and may include other suitable processing elements in otherembodiments. Components of the baseband circuitry may be suitablycombined in a single chip, a single chipset, or disposed on a samecircuit board in some embodiments. In some embodiments, some or all ofthe constituent components of the baseband circuitry 1404 and theapplication circuitry 1402 may be implemented together such as, forexample, on a system on a chip (SOC). In some embodiments, the basebandcircuitry 1404 may provide for communication compatible with one or moreradio technologies. For example, in some embodiments, the basebandcircuitry 1404 may support communication with an evolved universalterrestrial radio access network (EUTRAN) and/or other wirelessmetropolitan area networks (NYMAN), a wireless local area network(MILAN), a wireless personal area network (WPAN). Embodiments in whichthe baseband circuitry 1404 is configured to support radiocommunications of more than one wireless protocol may be referred to asmulti-mode baseband circuitry.

RF circuitry 1406 may enable communication with wireless networks usingmodulated electromagnetic radiation through a non-solid medium. Invarious embodiments, the RF circuitry 1406 may include switches,filters, amplifiers, etc. to facilitate the communication with thewireless network. RF circuitry 1406 may include a receive signal pathwhich may include circuitry to down-convert RE signals received from theFEM circuitry 1408 and provide baseband signals to the basebandcircuitry 1404. RE circuitry 1406 may also include a transmit signalpath which may include circuitry to up-convert baseband signals providedby the baseband circuitry 1404 and provide RF output signals to the FEMcircuitry 1408 for transmission.

In some embodiments, the RF circuitry 1406 may include a receive signalpath and a transmit signal path. The receive signal path of the RFcircuitry 1406 may include mixer circuitry 1406 a, amplifier circuitry1406 b and filter circuitry 1406 c. The transmit signal path of the RFcircuitry 1406 may include filter circuitry 1406 c and mixer circuitry1406 a. RF circuitry 1406 may also include synthesizer circuitry 1406 dfor synthesizing a frequency for use by the mixer circuitry 1406 a ofthe receive signal path and the transmit signal path. In someembodiments, the mixer circuitry 1406 a of the receive signal path maybe configured to down-convert RE signals received from the FEM circuitry1408 based on the synthesized frequency provided by synthesizercircuitry 1406 d. The amplifier circuitry 1406 b may be configured toamplify the down-converted signals and the filter circuitry 1406 c maybe a low-pass filter (LPF) or band-pass filter (BPF) configured toremove unwanted signals from the down-converted signals to generateoutput baseband signals. Output baseband signals may be provided to thebaseband circuitry 1404 for further processing. In some embodiments, theoutput baseband signals may, be zero-frequency baseband signals,although this is not a requirement. In some embodiments, mixer circuitry1406 a of the receive signal path may comprise passive mixers, althoughthe scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 1406 a of the transmit signalpath may be configured to up-convert input baseband signals based on thesynthesized frequency provided by the synthesizer circuitry 1406 d togenerate RF output signals for the FE M circuitry 1408. The basebandsignals may be provided by the baseband circuitry 1404 and may befiltered by filter circuitry 1406 c. The filter circuitry 1406 c mayinclude a low-pass filter (LPF), although the scope of the embodimentsis not limited in this respect.

In some embodiments, the mixer circuitry 1406 a of the receive signalpath and the mixer circuitry 1406 a of the transmit signal path mayinclude two or more mixers and may be arranged for quadraturedownconversion and/or upconversion respectively. In some embodiments,the mixer circuitry 1406 a of the receive signal path and the mixercircuitry 1406 a of the transmit signal path may include two or moremixers and may be arranged for image rejection (e.g., Hartley imagerejection). In some embodiments, the mixer circuitry 1406 a of thereceive signal path and the mixer circuitry 1406 a may be arranged fordirect downconversion and/or direct upconversion, respectively. In someembodiments, the mixer circuitry 1406 a of the receive signal path andthe mixer circuitry 1406 a of the transmit signal path may be configuredfor super-heterodyne operation.

In some embodiments, the output baseband signals and the input basebandsignals may be analog baseband signals, although the scope of theembodiments is not limited in this respect. In some alternateembodiments, the output baseband signals and the input baseband signalsmay be digital baseband signals. In these alternate embodiments, the RFcircuitry 1406 may include analog-to-digital converter (ADC) anddigital-to-analog converter (DAC) circuitry and the baseband circuitry1404 may include a digital baseband interface to communicate with the RFcircuitry 1406.

In some dual-mode embodiments, a separate radio IC circuitry may beprovided for processing signals for each spectrum, although the scope ofthe embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 1406 d may be afractional-N synthesizer or a fractional N/N+1 synthesizer, although thescope of the embodiments is not limited in this respect as other typesof frequency synthesizers may be suitable. For example, synthesizercircuitry 1406 d may be a delta-sigma synthesizer, a frequencymultiplier, or a synthesizer comprising a phase-locked loop with afrequency divider.

The synthesizer circuitry 1406 d may be configured to synthesize anoutput frequency for use by the mixer circuitry 1406 a of the RFcircuitry 1406 based on a frequency input and a divider control input.In some embodiments, the synthesizer circuitry 1406 d may be afractional N/N+1 synthesizer.

In some embodiments, frequency input may be provided by a voltagecontrolled oscillator (VCO), although that is not a requirement. Dividercontrol input may be provided by either the baseband circuitry 1404 orthe applications processor 1402 depending on the desired outputfrequency. In some embodiments, a divider control input (e.g., N) may bedetermined from a look-up table based on a channel indicated by theapplications processor 1402.

Synthesizer circuitry 1406 d of the RF circuitry 1406 may include adivider, a delay-locked loop (DLL), a multiplexer and a phaseaccumulator. In some embodiments, the divider may be a dual modulusdivider (DMD) and the phase accumulator may be a digital phaseaccumulator (DPA). In some embodiments, the DMD may be configured todivide the input signal by either N or N+1 (e.g., based on a carry out)to provide a fractional division ratio. In some example embodiments, theDLL may include a set of cascaded, tunable, delay elements, a phasedetector, a charge pump and a D-type flip-flop. In these embodiments,the delay elements may be configured to break a VCO period up into Ndequal packets of phase, where Nd is the number of delay elements in thedelay line. In this way, the DLL provides negative feedback to helpensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 1406 d may be configured togenerate a carrier frequency as the output frequency, while in otherembodiments, the output frequency may be a multiple of the carrierfrequency (e.g., twice the carrier frequency, four times the carrierfrequency) and used in conjunction with quadrature generator and dividercircuitry to generate multiple signals at the carrier frequency withmultiple different phases with respect to each other. In someembodiments, the output frequency may be a I-O frequency (ITO). In someembodiments, the RF circuitry 1406 may include an IQ/polar converter.

FEM circuitry 1408 may include a receive signal path which may includecircuitry configured to operate on RF signals received from one or moreantennas 1140, amplify the received signals and provide the amplifiedversions of the received signals to the RF circuitry 1406 for furtherprocessing. FEM circuitry 1408 may also include a transmit signal pathwhich may include circuitry configured to amplify signals fortransmission provided by the RF circuitry 1406 for transmission by oneor more of the one or more antennas 1410.

In some embodiments, the FEM circuitry 1408 may include a TX/RX switchto switch between transmit mode and receive mode operation. The FEMcircuitry may include a receive signal path and a transmit signal path.The receive signal path of the FEM circuitry may include a low-noiseamplifier (LNA) to amplify received RF signals and provide the amplifiedreceived RF signals as an output (e.g., to the RF circuitry 1406). Thetransmit signal path of the FEM circuitry 1408 may include a poweramplifier (PA) to amplify input RF signals (e.g., provided by RFcircuitry 1406), and one or more filters to generate RF signals forsubsequent transmission (e.g., by one or more of the one or moreantennas 1410.

In some embodiments, the LIE device 1400 may include additional elementssuch as, for example, memory/storage, display, camera, sensor, and/orinput/output (I/O) interface.

EXAMPLES

Example 1 is an apparatus of a user equipment 200 (UE), the apparatuscomprising: transceiver circuitry and processing circuitry 306. Thetransceiver circuitry configured to: connect to a master cell group(MCG) via a master Evolved Node B 502 (eNB) and a secondary cell group(SCG) via a secondary eNB 503; receive a first reference signal from themaster eNB 502; and receive a second reference signal from a secondaryeNB 503. The processing circuitry 306 configured to: calculate a systemframe number (SFN) and subframe timing difference 410 (SSTD) based onthe first reference signal and the second reference signal; generate ameasurement report 400 having a synchronization indicator 450 based onthe calculated SSTD 410; and wherein the transceiver circuitry isfurther configured to send the generated measurement report 400 to themaster eNB 502.

Example 2 includes the apparatus of Example 1, wherein the firstreference signal includes a master information block (MIB) having SFNinformation for the MCG, and wherein the second reference signalincludes a MIB having a SFN information for the SCG.

Example 3 includes the apparatus of the above examples, wherein the SSTD410 includes a SFN timing difference between the MCG and the SCG that iscalculated based on the SFN information for the MCG and the SFNinformation for the SCG.

Example 4 includes the apparatus of the above examples, wherein thefirst reference signal includes a frame boundary timing of the MCG andthe second reference signal includes a frame boundary timing of the SCG,and wherein the SSTD 410 includes a frame boundary offset between theMCG and the SCG that is calculated based on the frame boundary timing ofthe MCG and the frame boundary timing of the SCG.

Example 5 includes the apparatus of Example 4, wherein the frameboundary offset between the MCG and the SCG is calculated by subtractingthe frame boundary timing of the SCG from the frame boundary timing ofthe MCG.

Example 6 includes the apparatus of Example 4, wherein the SSTD 410includes a subframe boundary offset measurement, the subframe boundaryoffset measurement being calculated from the frame boundary timingbetween the MCG and the SCG.

Example 7 includes the apparatus of Example 6, wherein the transceivercircuitry is further configured to: receive, from the MeNB 502, a marginvalue, the margin value being predetermined by a network operatorassociated with the MeNB 502; and wherein the synchronization indicator450 is further based on the received margin value.

Example 8 includes the apparatus of Example 7, wherein thesynchronization indicator 450 indicates that the MCG and the SCG aresynchronous when the subframe boundary offset measurement in addition tothe received margin value is less than 33 micro-seconds.

Example 9 includes the apparatus of Example 7, wherein thesynchronization indicator 450 indicates that the MCG and the SCG areasynchronous when the subframe boundary offset measurement minus thereceived margin value is more than 33 micro-seconds.

Example 10 includes the apparatus of the above examples, wherein theprocessing circuitry includes a baseband processor to decode the firstreference signal and the second reference signal.

Example 11 includes the apparatus of the above examples, furthercomprising a first antenna coupled to the transceiver to receive thefirst reference signal from the master eNB, and a second antenna coupledto the transceiver to receive a second reference signal from thesecondary eNB.

Example 12 is a non-transitory computer-readable storage medium thatstores instructions 1324 for execution by one or more processors 1302 toperform operations for any of the Examples 1-11

Example 13 is an apparatus of an evolved node B 300 (eNB) configured tooperate as a master eNB 502 in a dual connectivity (DC) enhancementmode, the apparatus comprising: transceiver circuitry to: receive, froma user equipment 200 (UE), a measurement report 400, the measurementreport 400 having a system frame number (SFN) and subframe timingdifference 410 (SSTD); and a processing circuitry 206 to: determine asubframe boundary alignment of the master eNB 502 and a secondary eNB503 based on the received measurement report 400; and wherein thetransceiver circuitry is further configured to send the determinedsubframe boundary alignment.

Example 14 includes the apparatus of Example 13, wherein the determinedsubframe boundary alignment is sent using radio resource control (RRC)signaling.

Example 15 includes the apparatus of Examples 13-14, wherein theprocessing circuitry 206 is further configured to determine a quantizedstep based on the determined subframe boundary alignment, and thetransceiver circuitry is further configured to send the determinedquantized step.

Example 16 includes die apparatus of Example 13-15, wherein theprocessing circuitry 206 is further configured to determine adiscontinuous reception (DRX) pattern based on the determined subframeboundary alignment, and the transceiver circuitry is further configuredto send the determined DRX pattern.

Example 17 is the UE 200 of any of Examples 1-16.

Example 18 is the network entity of any of Examples 11-16.

Example 19 may include any of the methods of communicating in a wirelessnetwork as shown and described herein.

Example 20 may include any of the systems for providing wirelesscommunication as shown and described herein.

Example 21 may include any of the devices for providing wirelesscommunication as shown and described herein.

The foregoing description of one or more implementations provideillustration and description, but is not intended to be exhaustive or tolimit the scope of the embodiments disclosed herein to the precise formdisclosed. Modifications and variations are possible in light of theabove teachings or may be acquired from practice of variousimplementations of the embodiments disclosed herein.

Language

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures andfunctionality presented as separate components in example configurationsmay be implemented as a combined structure or component. Similarly,structures and functionality presented as a single component may beimplemented as separate components. These and other variations,modifications, additions, and improvements fall within the scope of thesubject matter herein.

Although an overview of the inventive subject matter has been describedwith reference to specific example embodiments, various modificationsand changes may be made to these embodiments without departing from thebroader scope of embodiments of the present disclosure. Such embodimentsof the inventive subject matter may be referred to herein, individuallyor collectively, by the term “invention” merely for convenience andwithout intending to voluntarily limit the scope of this application toany single disclosure or inventive concept if more than one is, in fact,disclosed.

The embodiments illustrated herein are described in sufficient detail toenable those skilled in the art to practice the teachings disclosed.Other embodiments may be used and derived therefrom, such thatstructural and logical substitutions and changes may be made withoutdeparting from the scope of this disclosure. The Detailed Description,therefore, is not to be taken in a limiting sense, and the scope ofvarious embodiments is defined only by the appended claims, along withthe full range of equivalents to which such claims are entitled.

As used herein, the term “or” may be construed in either an inclusive orexclusive sense. Moreover, plural instances may be provided forresources, operations, or structures described herein as a singleinstance. Additionally, boundaries between various resources,operations, modules, engines, and data stores are somewhat arbitrary,and particular operations are illustrated in a context of specificillustrative configurations. Other allocations of functionality areenvisioned and may fall within a scope of various embodiments of thepresent disclosure. In general, structures and functionality presentedas separate resources in the example configurations may be implementedas a combined structure or resource. Similarly, structures andfunctionality presented as a single resource may be implemented asseparate resources. These and other variations, modifications,additions, and improvements fall within a scope of embodiments of thepresent disclosure as represented by the appended claims. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

What is claimed is:
 1. An apparatus comprising: at least one processorconfigured to cause a user equipment (UE) to: configure the UE for DualConnectivity (DC) operation, wherein during the DC operation, in a radioresource control (RRC) connected mode the UE is configured to use radioresources from a master base station of a Master Cell Group (MCG) and asecondary base station of a Secondary Cell Group (SCG), and wherein aspan of the DC operation, the processor is configured to: decode firstsignaling received in a first subframe from the master base station, thefirst signaling including a first Master Information Block (MIB), decodesecond signaling received in a second subframe from the secondary basestation, the second signaling including a second MIB, wherein the firstMIB and the second MIB each include a system frame number; calculate, asubframe number (SFN) offset between the master base station and thesecondary base station, a frame boundary offset between the master basestation and the secondary base station, and a subframe boundary offsetbetween the master base station and the secondary base station; generatean SFN and subframe timing difference (SSTD) measurement reportincluding the SFN offset, the frame boundary offset, and the subframeboundary offset, wherein the SFN offset is reported as one of 1024values, wherein the frame boundary offset is reported as one of 10values, and wherein the subframe boundary offset is granulized to a stepsize of Q_step×Ts in the SSTD measurement report; and encode RRCsignaling for transmission to the master base station.
 2. The apparatusof claim 1, wherein the RRC signaling includes a MeasResults informationelement (IE) including the SFN offset, the frame boundary offset, andthe subframe boundary offset.
 3. The apparatus of claim 1, wherein theSSTD measurement report is to indicate: a synchronous DC operation whena difference in reception timing between the first subframe and thesecond subframe is 33 microseconds or less; or an asynchronous DCoperation when a difference in reception timing between the firstsubframe and the second subframe is greater than 33 microseconds.
 4. Theapparatus of claim 1, wherein the at least one processor is configuredto encode the RRC signaling to include the SSTD measurement report forone or both of alignment of a discontinuous reception (DRX) pattern oridentification of a measurement gap.
 5. The apparatus of claim 1,wherein Ts is equal to 1/(15000×2048) seconds and a value for Q_step is10.
 6. The apparatus of claim 1, wherein the apparatus further comprisestwo or more antennas and a transceiver, the two or more antennas and thetransceiver configured to transmit the SSTD measurement report in RRCsignaling to the master base station.
 7. A user equipment (UE)comprising: wireless communication circuitry; and at least one processorcoupled to the wireless communication circuitry configured to cause theUE to: configure the UE for Dual Connectivity (DC) operation, whereinduring the DC operation, in a radio resource control (RRC) connectedmode the UE is configured to use radio resources from a master basestation of a Master Cell Group (MCG) and a secondary base station of aSecondary Cell Group (SCG), and wherein as part of the DC operation, theprocessor is configured to: decode first signaling received in a firstsubframe from the master base station, the first signaling including afirst Master Information Block (MIB); decode second signaling receivedin a second subframe from the secondary base station, the secondsignaling including a second MIB, wherein the first MIB and the secondMIB each include a system frame number calculate, a subframe number(SFN) offset between the master base station and the secondary basestation, a frame boundary offset between the master base station and thesecondary base station, and a subframe boundary offset between themaster base station and the secondary base station; generate an SFN andsubframe timing difference (SSTD) measurement report including the SFNoffset, the frame boundary offset, and the subframe boundary offset;wherein the SFN offset is reported as one of 1024 values, wherein theframe boundary offset is reported as one of 10 values, and wherein thesubframe boundary offset is granulized to a step size of Q_step×Ts inthe SSTD measurement report; and encode RRC signaling for transmissionto the master base station.
 8. The UE of claim 7, wherein the RRCsignaling includes a MeasResults information element (IE) including theSFN offset, the frame boundary offset, and the subframe boundary offset.9. The UE of claim 7, wherein the SSTD measurement report is to indicateeither: a synchronous DC operation when a difference in reception timingbetween the first subframe and the second subframe is 33 microseconds orless; or an asynchronous DC operation when a difference in receptiontiming between the first subframe and the second subframe is greaterthan 33 microseconds.
 10. The UE of claim 7, wherein the at least oneprocessor is configured to encode the RRC signaling to include the SSTDmeasurement report for one or both of alignment of a discontinuousreception (DRX) pattern or identification of a measurement gap.
 11. TheUE of claim 7, wherein Ts is equal to 1/(15000×248) seconds and a valuefor Q_step is
 10. 12. An apparatus comprising: at least one processorconfigured to cause a master base station of a Master Cell Group (MCG)to: configure the master base station for Dual Connectivity (DC)operation, wherein during the DC operation, in a radio resource control(RRC) connected mode a user equipment (UE) is to use radio resourcesfrom the master base station and a secondary base station of a SecondaryCell Group (SCG), and wherein as part of the DC operation, the at leastone processor is configured to: encode first signaling for transmissionto the UE in a first subframe, the first signaling including a firstMaster Information Block (MIB), wherein the first MIB includes a systemframe number; and decode, from RRC signaling received from the UE, asubframe number and subframe timing difference (SSTD) measurement reportindicating a timing difference between the master base station and thesecondary base station, wherein the SSTD measurement report includes asubframe number (SFN) offset, a frame boundary offset, and a subframeboundary offset, wherein the SFN offset is reported as one of 1024values, wherein the frame boundary offset is reported as one of 10values, and wherein the subframe boundary offset is granulized to a stepsize of Q_step×Ts in the SSTD measurement report.
 13. The apparatus ofclaim 12, wherein the RRC signaling received from the UE includes aMeasResults information element (IE) including the SFN offset, the frameboundary offset, and the subframe boundary offset.
 14. The apparatus ofclaim 12, wherein the SSTD measurement report is to indicate either: asynchronous DC operation when a difference in reception timing betweenthe first subframe and the second subframe is 33 microseconds or less;or an asynchronous DC operation when a difference in reception timingbetween the first subframe and the second subframe is greater than 33microseconds.
 15. The apparatus of claim 12, wherein the at least oneprocessor is configured to decode the SSTD measurement report from theRRC signaling and determine an alignment of a discontinuous reception(DRX) based on the SSTD measurement report.
 16. The apparatus of claim12, wherein the at least one processor is configured to decode the SSTDmeasurement report from the RRC signaling and identify a measurement gapfor the UE based on the SSTD measurement report.
 17. The apparatus ofclaim 12, wherein Ts is equal to 1/(15000×2048) seconds and a value forQ_step is
 10. 18. A non-transitory computer-readable storage mediumstoring program instructions executable by one or more processors of amaster base station of a Master Cell Group (MCG) to cause the MCG to:configure the master base station for Dual Connectivity (DC) operation,wherein during the DC operation, in a radio resource control (RRC)connected mode a user equipment (UE) is to use radio resources from themaster base station and a secondary base station of a Secondary CellGroup (SCG), and wherein as part of the DC operation, the one or moreprocessors are configured to: encode first signaling for transmission tothe UE in a first subframe, the first signaling including a first MasterInformation Block (MIB), wherein the first MIB includes a system framenumber; decode, from RRC signaling received from the UE, a subframenumber and subframe timing difference (SSTD) measurement reportindicating a timing difference between the master base station and thesecondary base station, wherein the SSTD measurement report includes asubframe number (SFN) offset, a frame boundary offset, and a subframeboundary offset, wherein the SFN offset is reported as one of 1024values, wherein the frame boundary offset is reported as one of 10values, and wherein the subframe boundary offset is granulized to a stepsize of Q_step×Ts in the SSTD measurement report.
 19. The non-transitorycomputer-readable storage medium of claim 18, wherein the RRC signalingreceived from the UE includes a MeasResults information element (IE)including the SFN offset, the frame boundary offset, and the subframeboundary offset.
 20. The non-transitory computer-readable storage mediumof claim 18, wherein the SSTD measurement report is to indicate either:a synchronous DC operation when a difference in reception timing betweenthe first subframe and the second subframe is 33 microseconds or less;or an asynchronous DC operation when a difference in reception timingbetween the first subframe and the second subframe is greater than 33microseconds.
 21. The non-transitory computer-readable storage medium ofclaim 18, wherein the one or more processors are further configured todecode the SSTD measurement report from the RRC signaling and determineone of an alignment of a discontinuous reception (DRX) and a measurementgap based on the SSTD measurement report.
 22. The non-transitorycomputer-readable storage medium of claim 18, wherein Ts is equal to1/(15000×2048) seconds and a value for Q_step is 10.